Machine parts are often made by investment casting in which molten metal is cast in ceramic molds. The ceramic molds are made by coating wax models of the finished parts and melting the wax to leave the mold. These wax models are sometimes small and several are grouped on a wax support to save space. The wax models are dipped in melted wax and are joined to the support by hand. Sometimes a joint has air pockets or other cavities which are thereafter eliminated by melting the wax in the joint manually with a soldering iron. This is a time consuming operation but it must be done to prevent imperfect finished machine parts which cannot be used. Time spent in wax welding with a soldering iron and reworking imperfect joints and parts is a very large portion of the total time required to produce the machine parts. It is desirable to obtain a joint which is acceptable without manually soldering with a hand held soldering iron. It is desirable to join the wax models to the support in an efficient manner.